For internal combustion engines, such as diesel engines, nitrogen oxide (NOx) compounds may be emitted in the exhaust. To reduce NOx emissions, a selective catalytic reduction (SCR) process may be implemented to convert the NOx compounds into more neutral compounds, such as diatomic nitrogen and water, with the aid of a catalyst and a reductant. The catalyst may be included in a catalyst chamber of an exhaust system, such as that of a vehicle or power generation unit. A reductant, such as anhydrous ammonia, aqueous ammonia, or urea may be typically introduced into the exhaust gas flow prior to the catalyst chamber. To introduce the reductant into the exhaust gas flow for the SCR process, the reductant is introduced through a dosing module (doser), which may spray the reductant into an exhaust pipe of the exhaust system up-stream of the catalyst chamber. The SCR system may include one or more sensors to monitor conditions within the exhaust system.